Re: PUPA bugfixes

[Marco Gerards]

"Yoshinori K. Okuji" <address@hidden> writes:

> On Saturday 01 November 2003 17:41, Marco Gerards wrote:
> > Okuji, you told me it is better to check if a disk was swapped and if
> > not the disk cache should be flushed.  I have implemented that, but I
> > don't really like this solution.  Some BIOSes have bugs that prevent
> > this check from working and often it is impossible to check if the
> > BIOS has such bug.  I also dislike that the check takes some time.
> 
> What bug do you mean? Do you have a pointer to such information?
> Also, how much time does it take? 1ms, 100ms, 1s, or more?

A few hundred ms.

> > Now I have implemented this timeout globally, if there is a timeout
> > the entire cache is flushed for _all_ drives.  Is that ok for you or
> > should I implement it so it works per disk?
> 
> I'm not sure. I need more time to consider this issue.
> 
> In my experience, disk caching is important only for floppies. Hard disks are 
> not so important, because they have internal caching and they are quite fast. 
> I don't know how fast CDROM emulation mode is.
> 
> Normally, the user would normally use a single disk to boot up his/her 
> machine. I guess the number of disks concerning with boot stages would be at 
> most 3. So it might not be meaningful to manage disk caches in per disk 
> basis.
> 
> What do you think?

It is much easier to manage the cache globally and I see no real
disadvantages.  

> > And what do you think about adding "pupa-emu"?  I already sent in a
> > patch, but I didn't get feedback about it yet.  Do you want it?  If
> > you want it, what should I change before the patch can be committed?
> 
> Feel free to commit it. I have no objection.

I'm making some improvements again.  I will do this soon. :)

> BTW, your patch does not contain some files, such as times.h. It would be 
> better if you use the option -N to diff.

Oops.

Thanks,
Marco